Coerce lmerMod Objects to lmerModLmerTest

Coercing an lme4::lmer model-object (of class 'lmerMod') to a model-object of class 'lmerModLmerTest' involves computing the covariance matrix of the variance parameters and the gradient (Jacobian) of cov(beta) with respect to the variance parameters.

as_lmerModLmerTest(model, tol = 1e-08)

Arguments

model

and lmer model-object (of class 'lmerMod') – the result of a call to lme4::lmer()

tol

tolerance for determining of eigenvalues are negative, zero or positive

Value

an object of class 'lmerModLmerTest' which sets the following slots:

vcov_varpar

the asymptotic covariance matrix of the variance parameters (theta, sigma).

Jac_list

list of Jacobian matrices; gradients of vcov(beta) with respect to the variance parameters.

vcov_beta

the asymptotic covariance matrix of the fixed-effect regression parameters (beta; vcov(beta)).

sigma

the residual standard deviation.

See also

the class definition in lmerModLmerTest) and lmer

Author

Rune Haubo B. Christensen

Examples

m <- lme4::lmer(Reaction ~ Days + (Days | Subject), sleepstudy)
bm <- as_lmerModLmerTest(m)
slotNames(bm)
#>  [1] "vcov_varpar" "Jac_list"    "vcov_beta"   "sigma"       "resp"       
#>  [6] "Gp"          "call"        "frame"       "flist"       "cnms"       
#> [11] "lower"       "theta"       "beta"        "u"           "devcomp"    
#> [16] "pp"          "optinfo"